Effects of sunn pest (Eurygaster integriceps) damage ratio on physical, chemical, and technological characteristics of wheat

Sunn pest (SP) reduces both wheat yield and quality. Different researchers reported different sunn pest damage ratios (SPDR) in the range of 0.3 to 10%, which can lead to confusion on the determination of the level of destroying the technological quality of wheat. The aim of this study was to determine the effects of SPDR on two bread wheat quality. In the study, Golia and Sagittario wheat varieties with SPDR of 3.92 and 7.8% were used, respectively. Selection of SP damaged kernels in each variety was made manually. Experimental samples were prepared by separating damaged kernels from wheat bulk and then by mixing sound kernels at different ratios of 2, 4, 8, 12, 16, and 100%. These damaged samples were compared with undamaged sample (0% = control). Main physical, chemical, and technological characteristics of two variety wheat groups were determined. It was observed that SPDR in wheat bulk plays an important role in quality characteristics of wheat varieties. The increase in SPDR in wheat bulk caused a decrease on physical and technological characteristics. SPDR significantly affected thousands of kernels and hectolitre weight of wheat varieties. Crude fibre and ash contents of samples increased sharply; crude protein, dry gluten, and starch contents decreased partially; falling number, delayed zeleny sedimentation test, and delayed gluten index values decreased accurately depending on increasing level of SPDR in wheat bulk. It was found that the decrease in quality characteristics started with 2% SPDR and wheat-flour properties reduced significantly after 4% in both wheat varieties. © 2015 Wageningen Academic Publishers